The present invention relates to electrical reactors and more particularly to high voltage air core reactors for use in electrical power distribution systems.
1. Field of the Invention
High voltage air core reactors or power reactors are extensively used as components in electrical power distribution systems for a variety of well known purposes. Thus, there are current limiting reactors, filter reactors, ripple reactors, and shunt reactors, to name the more traditional types of power reactors. With the increased efficiencies of utility power distribution systems, these power reactors are subjected to increasingly higher levels of transient and fault currents. Associated with these high level currents flowing through power reactors are tremendous electrodynamic forces exerted on the coil turns. Consequently, the coil supporting structure must be mechanically robust if the power reactor is to survive the extremely high level fault and transient currents now commonplace in power distribution systems.
2. Description of the Prior Art
Presently, so-called "concrete" reactors are utilized to meet the mechanical design requirements of power reactors. Concrete reactors are characterized by an angular array of spaced columns cast in Portland cement or the like and in which the coil turns are imbedded. While concrete is quite adequate in compressive strength, it is not particularly strong in tension. To meet the current demands for a more robust coil supporting structure, the cross-section of the concrete columns must be enlarged or increased in number. In either case, the separation between columns is reduced. Consequently, a higher percentage of the reactor coil surface area is imbedded in concrete, leaving a lower percentage available for air cooling, which ideally is achieved by natural convection. Thus, unless extraordinary cooling measures are applied, the power reactor runs hotter and its losses increase.
It is accordingly an object of the present invention to provide a power reactor of significantly improved mechanical strength.
A further object is to provide a power reactor of the above character wherein its air-cooled efficiency is not prejudiced.
Another object of the present invention is to provide a power reactor of the above character which is efficient in design and operation, convenient to manufacture, and reliable in service.
Other objects of the invention will in part be obvious and in part appear hereinafter.